This antibody recognizes the modified base 5-Methylcytidine (5-MeCyd) found in DNA of plants and vertebrates. DNAmethylation is a DNA modification process, which is involved in the control of gene expression.Clone 33D3 has been developed to discriminate between the modified base 5-MeCyd and the normal counterpart Cytosine.Reports suggest that in tumours, DNA is frequently globally hypomethylated compared to the DNA from normal tissue.